Multi-channel mesh network

ABSTRACT

A method of selecting at least one routing path between and access node and a gateway is provided. The method includes the access node receiving over a plurality of channels, indicators from at least one upstream access node, the indicators providing information of selected upstream paths between each of the upstream access nodes and upstream gateways. The access node determines an optimal set of routing paths between the access node and at least one upstream gateway, based upon the indicators, the optimal set of routing paths including a combination of paths over multiple channels.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part (CIP) of U.S. patentapplication Ser. No. 10/693,721 filed on Oct. 25, 2003, titled “Methodand Apparatus to Provide a Routing Protocol for Wireless Devices” whichis a continuation of U.S. patent application Ser. No. 09/751,262 filedon Dec. 29, 2000, having the same title, and granted as U.S. Pat. No.6,704,301.

FIELD OF THE INVENTION

The invention relates generally to communication networks. Moreparticularly, the invention relates to a multi-channel mesh network.

BACKGROUND OF THE INVENTION

Wireless access devices are becoming more prevalent. Wireless access canbe implemented in many different forms, including connecting a wirelessaccess device (client) through a wireless mesh network that providesconnection to a wired device. FIG. 1 shows a wireless mesh network thatincludes a client device 140. The client device 140 is wirelesslyconnected to an access node 130. The wireless access node 130 iswirelessly connected to a wired gateway 110 through another wirelessaccess node 120. The wired gateway 110 can provide access to theinternet 100.

The transfer of information from the client 140 to the gateway 110 isgenerally two-way. That is, generally information flows from the clientdevice 140 to the gateway 110 (generally referred to as upstreamtraffic) and information flows from the gateway 110 to the client device140 (generally referred to as downstream traffic). The amount of datathat can flow between the gateway 110 and the client device 140 iscalled throughput. It is desirable to maximize the throughput ofwireless mesh networks.

The communication between the gateway 110, the access nodes 120, 130 andthe clients 140 is over a predefined transmission channel. For example,a specific range of the frequency spectrum is typically allocated forthe transmission between the devices. Typically, particular frequenciesof transmission operated better in particular environments. For example,certain ranges of transmission frequencies suffer from more multi-pathand fading than other ranges of frequency transmission in a particularsetting, such as, a downtown with car traffic. Other ranges oftransmission frequencies suffer more multi-path and fading than otherranges of frequency transmission in other settings, such as, a forest.

Mesh networks can alleviate the effects of fading and multi-path byproviding routing path alternatives. However, mesh networks having asingle transmission frequency can still suffer from transmission signaldegradation.

Upstream traffic of an access node can suffer from congestion if a largenumber of clients are connected to the access node. That is, a largenumber of clients demanding high data rates can stress the upstream datapath between the access node and the gateway.

It is desirable to have a mesh network having improved throughput, andreliable communication between access nodes and gateways of the meshnetwork.

SUMMARY OF THE INVENTION

The invention includes an apparatus and method for a multiple channelmesh network that provides enhanced throughput and transmissionreliability.

A first embodiment of the invention includes a method of selecting atleast one routing path between and access node and a gateway. The methodincludes the access node receiving over a plurality of channels,indicators from at least one upstream access node, the indicatorsproviding information of selected upstream paths between each of theupstream access nodes and upstream gateways. The access node determinesan optimal set of routing paths between the access node and at least oneupstream gateway, based upon the indicators, the optimal set of routingpaths including a combination of paths over multiple channels.

Another embodiment of the invention includes a method of routing datapackets through a wireless mesh network. The mesh network includes atleast one gateway and a plurality of access nodes. The method includeseach access node receiving over a plurality of channels, indicators fromat least one upstream device. If the at least one upstream device is anupstream access node, the indicators provide information of selectedupstream paths between each of the upstream access nodes and upstreamgateways, and each access node determines an optimal set of routingpaths between the access node and at least one upstream gateway, basedupon the indicators, the optimal set of routing paths including acombination of paths over multiple channels.

Another embodiment of the invention includes an access node. The accessnode includes a plurality of radios operable on a plurality oftransmission channels, the radios receiving over a plurality ofchannels, indicators from at least one upstream access node, theindicators providing information of selected upstream paths between eachof the upstream access nodes and upstream gateways. The access nodefurther includes a means for determining an optimal set of routing pathsbetween the access node and at least one upstream gateway, based uponthe indicators, the optimal set of routing paths including a combinationof paths over multiple channels.

Another embodiment of the invention includes a mesh network. The meshnetwork includes at least one gateway, each gateway transmitting beaconsthrough a plurality of transmission channels. The mesh network includesplurality of access nodes. Each access node receives beacons through atleast one of the transmission channels. Each access node selects routingpaths based upon path indicator information within the received beacons,the routing paths selected from the plurality of transmission channels,the selected set of routing paths including a combination of paths overmultiple channels. The mesh network further includes a client, theclient receiving beacons through at least one of the transmissionchannels from at least one of the access nodes.

Other aspects and advantages of the present invention will becomeapparent from the following detailed description, taken in conjunctionwith the accompanying drawings, illustrating by way of example theprinciples of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a network device connected to a client through a meshnetwork.

FIG. 2 shows a mesh network that includes multiple transmissionchannels, according to an embodiment of the invention.

FIG. 3 shows an access node according to an embodiment of the invention.

FIG. 4 shows a mesh network that illustrates principles of an embodimentof the invention.

FIG. 5 shows another mesh network that illustrates additional principlesof an embodiment of the invention.

FIG. 6 is a flow chart showing steps included within an embodiment ofthe invention.

FIG. 7 is a flow chart showing steps included within another embodimentof the invention.

DETAILED DESCRIPTION

As shown in the drawings for purposes of illustration, the invention isembodied in a multiple channel mesh network that provides enhancedthroughput and transmission reliability.

FIG. 2 shows a mesh network that includes multiple transmissionchannels. The mesh network includes gateways 202, 204, access nodes 212,214 and a client 220. Generally, wireless transmission signals providecommunication between the gateways 202, 204, the access nodes 212, 214and client 220. As shown in FIG. 2, the transmission signals can travelthrough one or more of M available transmission channels Ch1-ChM.

A gateway is typically a wired device that provides a wireless accessnode access to a network. The gateway is a network entity that maintainsan address-mapping table for each client. The address-mapping tablegenerally includes a MAC-IP address mapping for the client devices. Aswill be described, one or more gateways can correspond with each accessnode, and each gateway can service several access nodes.

An access node generally includes any point of attachment of a clientwith the mesh network. The access node can be a wireless access point, awired access point, a router, a hub, a gateway, or any other networkingdevice capable of attachment to a client.

A client generally can include a laptop computer, a personal digitalassistant (PDA), a cell-phone, or any other device that includes asinterface card adaptable for use with the mesh network of the invention.

A downlink interface is a network interface (logical or physical) thatattaches an access node to a client device. An access node can have morethat one downlink interface. All other interfaces other than downlinkinterfaces are termed uplink interfaces.

The mesh network has been generalized to include N gateways 202, 204.Depending upon the quality of each of the available communicationchannels available, one or more gateways 202, 204 can maintaincommunication with each client

Multiple transmission channels (Ch1-ChM) exist between the devices ofthe mesh network. The channels are generalized to include M channels,represented as channel CH1 to channel ChM. The multiple channelsavailable for communication between the devices (gateways, access nodesand clients), allows the mesh network to optimally select one or more ofthe channels for communication between each of the devices. The channelsselection can be based upon maximal throughput of communication betweena client and a gateway, or for maximal reliability of communicationbetween a client and a gateway or some other criteria. For example, afirst channel (such as an 802.11(g)) transmission channel may providegreater data transmission rates than all other available channels, andanother channel (such as an 802.11(b)) transmission channel may providemore reliable data transmission rates than all other available channels.A selection may include one transmission channel or the other, or mayinclude both depending upon the selection criteria.

An embodiment of the mesh network includes the gateways 202, 204transmitting beacons. The beacons can be transmitted through a pluralityof the available transmission channels Ch1-ChM. The beacons are receivedby access nodes 212, 214 if the access nodes 212, 214 are physicallylocated with respect to the transmitting gateway such that at least oneof the transmission channels allows successful transmission of thebeacons to the access nodes 212, 214. Access nodes 212, 214 that areable to receive a beacon, re-broadcast a corresponding beacon forreception by downstream devices (other access nodes or clients). Thispermits each access node to determine at least one path to one or moregateways.

For one embodiment, the access nodes transmit reverse beacons back tothe gateways. Thus, the gateway has a full path to each access node, andeach access node has a path to its nearest neighbors (gateway or accessnodes), and knows which of those paths leads to the gateway. Therefore,the access node and the gateway can communicate.

For another embodiment, when an access node wishes to connect thegateway, it sends a connection request, through the known path to the atleast one gateway. This connection request includes at least one knownpath to the gateway. When the at least one gateway receives the request,it becomes aware of the path to the requesting access node, as well asall intervening nodes. The at least one gateway uses this information torespond to the request, and add the data to its routing table/accessnode tree.

Each access node receives beacons that provide indicators of availablerouting paths to an upstream gateway. When a gateway 202, 204 broadcastsa beacon, the beacon is received by all first-level access nodes. Thebeacon is used to establish a route from each access node to thegateway. First level access nodes are defined by the fact that theyreceive data directly from the gateway. The first level access nodesre-broadcast the beacon data over multiple channels, attachingadditional path data to it. The additional path information indicates tothe second level access nodes that the path to the gateway includes thefirst level access node.

For one embodiment, the link quality of the beacon received determineswhether that beacon is rebroadcast by the system. If the quality of thebeacon is above a determined threshold, it is rebroadcast. Otherwise, itis not. For one embodiment, link quality is determined by persistence,i.e. the number of times in the last several routing cycles that theparticular beacon was received. For one embodiment, the link qualityreflects the reliability of paths to the gateway, as determined by thebeacon being available for a reasonable time. For one embodiment, thelink quality reflects the end-to-end throughput between the access nodeand the gateway. The link quality is determined by continuouslymonitoring the beacons as they are received in every cycle. Whenever thebeacon is not received in a cycle, the link quality associated with thatpath is decreased. The beacon is only transmitted if its link quality issufficiently high.

For another embodiment, the depth of re-broadcast is determined for thesystem. Thus, for example, an access node may rebroadcast a beacon onlyif there are 5 or fewer hops between the access node and the gateway.For another embodiment, other link quality factors, such as trafficcongestion, battery status of upstream access nodes, thickness of thepipeline, backend (i.e. gateway) capacity, latency, or other factors maybe used to determine whether the beacon should be rebroadcast.

After every access node has received at least one beacon, every accessnode has the address of at least one upstream access node, over multipletransmission channels, which leads to at least one of the gateways. Forone embodiment, each access node also has at least one path to thegateway. A reverse beacon is then sent out through the access nodes, upto the gateways. The reverse beacon permits the gateways to establish afull access node trees, enabling the gateways to access all accessnodes. Furthermore, the reverse beacon informs each access node whatdownstream nodes access the gateways through this access node.

Each access node has at least one upstream node, and may have aplurality of downstream nodes. Upstream nodes are the nodes that arebetween the access node and the gateway. For a level one access node,there is only one upstream node to at least one of the gateways. For alevel four access node, there are four upstream nodes, which defines oneof the access node's paths to the gateway. Downstream nodes are nodesthat receive the beacon from a particular access node, and that defineat least one of their paths to the gateway through that access node. Dueto the fact that multiple transmission channels are available, aparticular node could be a level one access node over one set oftransmission channels, and a level two, three or four node, over anotherset of transmission channels. Therefore the level of the access node isdetermined in reference to the set of transmission channels.

For another embodiment, the reverse beacon need not be sent. Not sendingthe reverse beacon means that the gateway can't initiate sending amessage to an access node. Rather, the gateway must wait for a requestfrom the access node. That request includes a path to the access node.Also, the only method of access-node-to-access-node communication insuch a system is by sending the message through the gateway. In somewireless systems this is sufficient because access to the gateway, whichprovides access to the general Internet, is the primary use.

Although only a limited number of gateways 202, 204 and access nodes212, 214 are shown in FIG. 2, it should be understood by one skilled inthe art that an almost unlimited numbers of access nodes 212, 214, atalmost unlimited number of hops from the gateways 202, 204 may beimplemented. For one embodiment, the gateway capacity determines thenumber of access nodes that may be coupled to the gateway. Thus, forexample, if the gateway can handle 10 simultaneous connections tovarious access nodes, then up to 100 access nodes may be coupled to thegateway. This indicates that no more than 1-in-10 access nodes accessthe gateway at any one time. This assures that the access nodes neverhave to wait for the gateway. Depending on the latency that isacceptable, which varies by function (e.g. voice v. data latency), thegateway may support a certain number of access nodes of each function.

The gateways play a central role in the discovery of routes by theaccess nodes. At periodic intervals, the gateways each originate a“beacon” which is broadcast to all access nodes within receiving rangeof the gateways, over some or all available transmission channels. Thetime interval between successive broadcasts of the beacons defines arouting cycle. The beacon is a routing packet—a short data packet thatcontains the address of the gateway. For one embodiment, the beaconincludes the following information: (1) a sequence number whichidentifies which routing cycle it initiates, 2) the address (MAC or IP)of the gateway, 3) a Traffic Monitoring Code (TMC). For one embodimentthe TMC may be omitted. For one embodiment, the address of the gatewaymay be included only in the ethernet header or IP header of the beaconmessage. For one embodiment, the beacon may contain additional data suchas the bandwidth of the wired connection.

Operationally, the embodiment of FIG. 2 includes methods of selecting atleast one routing path between and access node and a gateway. Themethods can include each access node receiving over a plurality ofchannels, indicators from at least one upstream access node or gateway,the indicators providing information of selected upstream paths betweeneach of the upstream access nodes and upstream gateways. The accessnodes determine an optimal set of routing paths between the access nodeand at least one upstream gateway, based upon the indicators, theoptimal set of routing paths including a combination of paths overmultiple channels.

FIG. 3 shows an access node 300 that includes multiple radios 312, 314,316, 318, 320, operable over multiple transmission channels. Forexample, a first radio 312 and a second radio 314 can be operable withtransmission signals of a first transmission channel, a third radio 316and a fourth radio 318 can be operable with transmission signals of asecond transmission channel, and a fifth radio can be operable withtransmission signals of a third transmission channel. Any combination oftransmission channels can be operable at any given time, for bothupstream communication and downstream communication. That is, forexample, the first radio 312 and the third radio 316 may simultaneouslyprovide upstream communication with one or more upstream devices, whilethe second radio 314, the fourth radio 318 and the fifth radio 320 maysimultaneously provide downstream communication with one or moredownstream devices. Alternatively, for example, the second radio 314 mayprovide upstream communication with an upstream device, and the thirdradio 316 may provide downstream communication with a downstream device,while the first radio 312, the fourth radio 318 and the fifth radio 320are non-operating. Any combination of radios operable with upstream anddownstream devices is possible.

A controller 330 provides control over which of the radios 312, 314,316, 318, 320 are operable with which upstream and downstream devices.The determination between which radios are operable in either thedownstream or upstream communications can be made by analyzing routingindicators within beacons received from upstream devices.

Generally, an access node of the mesh network of FIG. 2, includes aplurality of radios operable on a plurality of transmission channels.The radios receive over a plurality of channels, indicators from atleast one upstream access node. The indicators provide information ofselected upstream paths between each of the upstream access nodes andupstream gateways. The access node further includes a means fordetermining an optimal set of routing paths between the access node andat least one upstream gateway, based upon the indicators. Generally, theoptimal set of routing paths includes a combination of paths overmultiple channels.

Exemplary transmission channels include transmission channels accordingto at least one of 802.11(a), 802.11(b), 802.11(g), 802.11(n), 802.16transmission protocols. Additional transmission protocols operating overlicensed or unlicensed wireless frequencies may also be used.Determining an optimal set of routing paths can include determining apath quality of the available paths, and selecting the optimal pathsbased upon selection criteria. Exemplary selection criteria includesinformation throughput of the routing paths, or the number of hops ofthe routing paths. The number of hops can be determined by including hopindicators within the beacons, and incrementing the hop indicators witheach hop. Generally, the optimal set of routing paths includes acombination of paths through multiple upstream access nodes. The pathsare generally determined by the path indicators. Exemplary pathindicators include beacons that are initially transmitted from gateways,over multiple transmission channels. All access nodes receiving beaconscan modify the beacons with upstream routing information, and thenretransmit the beacons over multiple channels.

FIGS. 4 and 5 show exemplary mesh networks that include at least some ofthe principles described. The embodiments are provided to aid inunderstanding the breadth of the principles, and are not to be limiting.

FIG. 4 shows a mesh network that includes a gateway 410 connected to anetwork 405, access nodes 422, 424, 426, 428, and a client 430. Theclient 430 of FIG. 4 includes only a single transmission channel Ch(2).The single transmission channel Ch(2), can be any one of a number ofpossible channels. For example, the single channel could be 802.11(a),802.11(b), 802.11(g), 802.11(n), or any other available transmissionchannel. The mesh network connections upstream from the client caninclude multiple paths over a combination of transmission channels.Here, the client 430 has two upstream data paths to the gateway 410through a combination of transmission channels Ch(1), Ch(2), Ch(3).

Each access node receives beacons over multiple transmission channelsthat originate at the gateway 410. Beacons that are received and includea predetermined level of transmission quality, are modified by thereceiving access node, and retransmitted. The beacons are modified toinclude the routing information of the receiving access node. Oneembodiment includes the access nodes selecting the beacons of thetransmission channels having the best transmission quality. Anotherembodiment includes the access node selecting a combination of beaconsreceived over multiple transmission channels. Effectively, links betweengateways and access nodes that include multiple transmission channelsinclude greater bandwidths than single transmission channel links.Therefore, higher bandwidth and more reliable links are possible withmultiple transmission channel links than with single transmissionchannel links.

The gateway 410 is typically hardwired to the network. The embodiment ofFIG. 4 includes one gateway 410. However, the access nodes of FIG. 4 canlink to multiple gateways if this improves the bandwidth and reliabilityof the mesh network.

As shown, the link between the gateway 410 and the access node 422 isover the transmission channel Ch(1). The access node 422 selected thebeacons transmitted from the gateway 410 over the transmission channelCh(1) over the beacons transmitted over other available channels, andbeacons transmitted from other access nodes and other gateways.

The link between the access node 428 and the access node 422 is over thetransmission channels Ch(2) and Ch(3). The access node 428 selected thebeacons transmitted from the access node 422 over the combination oftransmission channels Ch(2) and Ch(3) over the beacons transmitted fromother available channels, or beacons transmitted from other access nodesor gateways.

The link between the gateway 410 and the access node 424 is over thetransmission channels Ch(1) and Ch(2). The access node 424 selected thebeacons transmitted from the gateway 410 over the combination oftransmission channels Ch(1) and Ch(2) over the beacons transmitted fromother available channels, or beacons transmitted from other access nodesor gateways.

The link between the access node 426 and the access node 424 is over thetransmission channels Ch(1). The access node 426 selected the beaconstransmitted from the access node 424 over the transmission channelsCh(1) over the beacons transmitted from other available channels, orbeacons transmitted from other access nodes or gateways.

The link between the access node 428 and the access node 426 is over thetransmission channels Ch(3). The access node 428 selected the beaconstransmitted from the access node 426 over the transmission channelsCh(3) over the beacons transmitted from other available channels, orbeacons transmitted from other access nodes or gateways.

The access node 428 includes two data paths to the gateway 410. The twodata paths include beacons that as a combination path, provides theupstream data path that best meets the selection criteria of the accessnode 428. As previously described, the selection criteria can includedata throughput, and path reliability.

FIG. 5 shows a mesh network that include a gateway 510 connected to anetwork 505, access nodes 522, 524, 526, and a client 530. The client530 of this embodiment includes multiple transmission channels Ch(1),Ch(2), Ch(3). The client 530 as shown, include multiple data paths tothe gateway 510 through multiple access node over multiple combinationsof transmission channels Ch(1), Ch(2), Ch(3), Ch(4).

FIG. 6 is a flow chart showing steps included within a method ofselecting at least one routing path between an access node and agateway. A first step 610 includes the access node receiving over aplurality of channels, indicators from at least one upstream accessnode, the indicators providing information of selected upstream pathsbetween each of the upstream access nodes and upstream gateways. Asecond step 620 includes the access node determining an optimal set ofrouting paths between the access node and at least one upstream gateway,based upon the indicators, the optimal set of routing paths including acombination of paths over multiple channels.

The plurality of channels can include, but are not limited totransmission channels according to at least one of 802.11(a), 802.11(b),802.11(g), 802.11(n), 802.16 transmission protocols. The access node candetermine an optimal set of routing paths by determining a path qualityof the available paths, and selecting the optimal paths based upon aselection criteria. Exemplary selection criteria include informationthroughput of the routing paths and a number of hops of the routingpaths. The optimal set of routing paths typically includes at least oneof a plurality of possible routing paths. The optimal set of routingpaths generally includes a combination of paths through multipleupstream access nodes. The optimal routing paths can includecombinations of individual channels or combinations of multiplechannels.

The indicators can include beacons originating at the gateways. Thebeacons are retransmitted by the upstream access nodes after the beaconshave been modified to include selected upstream routing information. Thebeacons can include hop indicators that are incremented with each hop.As stated above, a hop is that transmission of a beacon from a gatewayor access node, to a downstream access node. The access nodes can alsosend reverse beacons back to the gateways. The reverse beacons allow thegateways to construct a client tree, thereby providing each gateway withat least one path including multiple channels to all clients and accessnodes.

FIG. 7 is a flow chart showing steps included within another embodimentof a method of routing data packets through a wireless mesh network. Themesh network includes at least one gateway and a plurality of accessnodes. A first step 710 includes each access node receiving over aplurality of channels, indicators from at least one upstream device. Asecond step 720 includes if the at least one upstream device is anupstream access node, the indicators providing information of selectedupstream paths between each of the upstream access nodes and upstreamgateways. A third step 730 includes each access node determining anoptimal set of routing paths between the access node and at least oneupstream gateway, based upon the indicators, the optimal set of routingpaths including a combination of paths over multiple channels.

As stated above, the plurality of channels can include, but are notlimited to transmission channels according to at least one of 802.11(a),802.11(b), 802.11(g), 802.11(n), 802.16 transmission protocols. Theaccess node can determine an optimal set of routing paths by determininga path quality of the available paths, and selecting the optimal pathsbased upon one or more selection criteria. The indicators can includebeacons originating at the gateways. The beacons are retransmitted byupstream access nodes, after the beacons have been modified to includeselected upstream routing information. The beacons can include hopindicators that are incremented with each hop. As stated above, a hop isthat transmission of a beacon from a gateway or access node, to adownstream access node. The access nodes can also send a reverse beaconsback to the gateways. The reverse beacons allow the gateways toconstruct a client tree, thereby providing each gateway with at leastone path including multiple channels to all clients.

Although specific embodiments of the invention have been described andillustrated, the invention is not to be limited to the specific forms orarrangements of parts so described and illustrated. The invention islimited only by the appended claims.

1. A method of selecting at least one routing path between an accessnode and at least one of a plurality of gateways comprising: at leastone gateway originating and simultaneously broadcasting beacons from aplurality of radios over a plurality of channels, each channel differentfrom other of the plurality of channels, at least one radio broadcastingthe beacons over a corresponding one of the plurality of channels, thebeacons being broadcast over each of the plurality of channels at apredetermined rate; the access node simultaneously receiving over aplurality of channels with a plurality of access node radios, at leastone access node radio corresponding with each of the plurality ofchannels, beacons from at least one upstream access node or gateway, thebeacons providing information of selected upstream paths between each ofthe upstream access nodes and the plurality of gateways; and the accessnode selecting a routing path between the access node and at least oneof the plurality of gateways, based on a persistence of successfullyreceived beacons, the selected routing path including multiple differentchannels; the access node simultaneously re-broadcasting beacons withthe plurality of access node radios, the re-broadcast beaconscorresponding to the selected routing path, over each of the pluralityof channels, the rebroadcast beacons modified by the access node toinclude information of the selected routing path.
 2. The method of claim1, wherein the plurality of channels comprises transmission channelsaccording to at least two of 802.11(a), 802.11(b), 802.11(g), 802.11(n)transmission protocols.
 3. The method of claim 1, wherein the selectioncriteria is additionally based upon an information throughput of therouting paths.
 4. The method of claim 1, wherein the selection criteriais additionally based upon a number of hops of the routing paths.
 5. Themethod of claim 1, wherein beacons that are successfully received by theupstream access nodes are rebroadcast by the upstream access nodes overmultiple different channels after the beacons have been modified toinclude selected upstream routing information of the upstream accessnodes.
 6. The method of claim 1, wherein selected upstream paths betweeneach upstream access node and upstream gateways includes a combinationof paths, over multiple different channels, and upstream paths areselected based on a persistence of successfully received broadcast andrebroadcast beacons.
 7. The method of claim 1, wherein selected upstreampaths between each upstream access node and upstream gateways areselected based upon path quality.
 8. The method of claim 7, wherein thepath quality is determined by an information throughput of the upstreampaths.
 9. The method of claim 7, wherein the path quality is determinedby a number of hops included within the upstream paths.
 10. The methodof claim 1, further comprising the access node transmitting a modifiedbeacon over a plurality of channels, the modified beacon including theoptimal set of routing paths between the access node and the at leastone upstream gateway.
 11. The method of claim 1, further comprising:sending a reverse beacon to the gateway; and constructing a client treein the gateway, wherein the gateway has at least one path includingmultiple channels to all clients.